This invention relates to heat curable polymers. More specifically, this invention relates to heat curable polymers that are particularly useful as coatings for wire or cable.
Prior methods of curing, i.e. crosslinking, polymers include use of various peroxides. A mixture of polymer and a small amount of peroxide is prepared, and the mixture is cured with heat. The difficulty with this method is that the curing process generates volatile compounds which vaporize at curing temperature if the pressure is low. Hence, unless the curing is carried out at high pressure in expensive pressure chambers, the cured polymer will have voids caused by the vaporized material.
Another method of curing polymer is by use of electron beams. However, this method requires expensive electron beam generating apparatus, and is unacceptably slow if the polymer being cured is thick.
U.S. Pat. No. 3,646,155 (Scott) discloses a water curable polymer. However, its manufacturer requires use of relatively expensive silane compounds and requires intimate contact with water to effect cross-linking.